Captchas now work on registration. Missing x-forwarded-for config arg support. Missing reloading a new captcha on the web client / displaying a sensible error message.

synapse/handlers/register.py

@@ -17,7 +17,7 @@
 from twisted.internet import defer
 
 from synapse.types import UserID
-from synapse.api.errors import SynapseError, RegistrationError
+from synapse.api.errors import SynapseError, RegistrationError, InvalidCaptchaError
 from ._base import BaseHandler
 import synapse.util.stringutils as stringutils
 from synapse.http.client import PlainHttpClient
@@ -38,7 +38,7 @@ class RegistrationHandler(BaseHandler):
         self.distributor.declare("registered_user")
 
     @defer.inlineCallbacks
-    def register(self, localpart=None, password=None, threepidCreds=None):
+    def register(self, localpart=None, password=None, threepidCreds=None, captcha_info={}):
         """Registers a new client on the server.
 
         Args:
@@ -51,6 +51,19 @@ class RegistrationHandler(BaseHandler):
         Raises:
             RegistrationError if there was a problem registering.
         """
+        if captcha_info:
+            captcha_response = yield self._validate_captcha(
+                captcha_info["ip"], 
+                captcha_info["private_key"],
+                captcha_info["challenge"],
+                captcha_info["response"]
+            )
+            if not captcha_response["valid"]:
+                raise InvalidCaptchaError(
+                    error_url=captcha_response["error_url"]
+                )
+            else:
+                logger.info("Valid captcha entered from %s", captcha_info["ip"])
 
         if threepidCreds:
             for c in threepidCreds:
@@ -153,5 +166,37 @@ class RegistrationHandler(BaseHandler):
         )
         defer.returnValue(data)
         
+    @defer.inlineCallbacks
+    def _validate_captcha(self, ip_addr, private_key, challenge, response):
+        """Validates the captcha provided.
+        
+        Returns:
+            dict: Containing 'valid'(bool) and 'error_url'(str) if invalid.
+        
+        """
+        response = yield self._submit_captcha(ip_addr, private_key, challenge, response)
+        # parse Google's response. Lovely format..
+        lines = response.split('\n')
+        json = {
+            "valid": lines[0] == 'true',
+            "error_url": "http://www.google.com/recaptcha/api/challenge?error=%s" % lines[1]
+        }
+        defer.returnValue(json)
+        
+    @defer.inlineCallbacks
+    def _submit_captcha(self, ip_addr, private_key, challenge, response):
+        client = PlainHttpClient(self.hs)
+        data = yield client.post_urlencoded_get_raw(
+            "www.google.com:80",
+            "/recaptcha/api/verify",
+            accept_partial=True,  # twisted dislikes google's response, no content length.
+            args={ 
+                'privatekey': private_key, 
+                'remoteip': ip_addr,
+                'challenge': challenge,
+                'response': response
+            }
+        )
+        defer.returnValue(data)